1. Field of the Invention
The present invention relates generally to a portable wireless terminal including a cellular phone, personal digital assistance (PDA), and hand held phone (HHP). In particular, the present invention relates to a user interfacing device for a portable wireless terminal, which enables a user to select one mode out of PDA mode and cellular phone mode.
2. Description of the Related Art
In general, a cellular phone means a mobile station which is capable of providing a user and another party with wireless communication service while performing wireless communication with a base station. Sometimes, the cellular phone is classified into a bar-type, a flip-type, or a folder-type phone according to its outward appearance. Also, depending on where a user puts on, the cellular phone could be classified into a wrist-type or a neck wearable-type phone. Further, the cellular phone could be classified according to usage or function, for example, a voice communication use phone, a visual communication use phone, a game use phone or an Internet communication use phone. In the future, however, a greater variety of phones equipped with enhanced wearing convenience and convenience of use will be widely available. In particular, a combined multi-functional wireless terminal equipped with diverse modes is expected to be popular.
Among other terminals listed above, a cellular phone currently being universalized includes a data input/output unit typically used for text messaging, a transmitting/receiving unit, and an antenna. As for the data input unit, a keypad having a plurality of keys is usually used, and as for the data output unit, a liquid crystal display (LCD) is used. Also, a microphone is used as the transmitting unit, and a speaker is used as the receiving unit. In the alternative, a touch screen or a voice recognition device can be used as the data input unit. If it is necessary to input more complex data, the user needed to purchase a personal digital assistant (PDA).
However, there are several problems associated with the wireless terminal currently being universalized. Although more people prefer lighter and smaller cellular phones, the small main body of the phone cannot be accomplished unless the keypad including the LCD and the plurality of keys is also miniaturized. However, if the LCD is miniaturized, the user will find it difficult to check the data thereon. Also, if the keypad is miniaturized, it will be hard to input data by pressing the keys using a finger. This is why some industries are hesitant to miniature the wireless terminal because they know it would be very difficult to make the cellular phone yet enlarge the LCD and the keypad at the same time.
Nevertheless, it is inevitable that a multi-functional wireless terminal will be developed to keep abreast of a greater variety of Internet environment, requiring more keys and a larger LCD to perform diverse functions. In other words, the wireless terminal currently being used is not sufficient to satisfy the user's different needs in addition to making phone calls, such as, sending emails or chatting through the PDA and receiving other additional services. Therefore, more keys and a large LCD are definitely necessary to keep up with growing needs of the users. That is to say, a data input/output device providing more convenience to the data input/output operation is desirable for the wireless terminal.